The invention pertains to an interface for light barrier arrangements.
In this context, the term xe2x80x9clight barrier arrangementxe2x80x9d refers to optoelectronic sensors that serve for monitoring a hazardous area, e.g., individual light barriers, light screens, light curtains, etc. Light barrier arrangements of this type contain control electronics that need to be configured in accordance with the respective conditions before commissioning, i.e., the control electronics need to be programmed or read out for diagnostic purposes. Conventional light barrier arrangements contain an interface for this purpose, wherein a socket, into which a diagnosis plug can be inserted, is screwed onto the interface. The process of screwing on the connecting socket is complicated and time-consuming. In addition, this can lead to sealing problems or the loss of individual parts, e.g., screws, etc. In addition, the attachment of the diagnosis interface may cause a maladjustment of the light barrier arrangement. This is particularly problematic if it is intended to use auxiliary diagnostic means for controlling the adjustment.
DE 42 16 242 A1 describes an interface component for sensors, e.g., light barriers, which contains a data interface and a parameter interface for connecting the sensors. In a configuration mode that is initiated by the switching operation of a magnetic switch, data are exchanged between a control unit and the sensors via the parameter interface.
The invention is based on the objective of improving an interface for light barrier arrangements in such a way that it has a simple design, can be easily handled and ensures a high degree of protection against dirt and moisture.
The basic principle of the invention consists of an optoelectronic data exchange that can be activated by a magnetically actuated switch.
The light barrier arrangement contains an interface component with a first optoelectronic communication device and the magnetically actuated switch. The magnetically actuated switch may simply consist of a xe2x80x9cReed contact.xe2x80x9d However, it would also be conceivable to utilize electromagnetic components, e.g., a photoresistance cell controlled by a magnetic field, Hall generators or electromagnetic sensors in the form of integrated circuits. The first communication device and the magnetically actuated switch cooperate with an external interface element that can be xe2x80x9cconnectedxe2x80x9d or xe2x80x9cattachedxe2x80x9d to the interface component of the light barrier arrangement, wherein said interface element contains an assigned second optoelectronic communication device and a magnet for actuating the switch. The first communication device contains a light transmitting element and a light receiving element in order to realize an infrared connection between the external interface element and the light barrier arrangement. The external interface element contains a communication device that is either realized in the form of a pair of light transmitting and light receiving elements or an optical waveguide, e.g., a fiber-optic waveguide, a prism or a mirror arrangement, for feeding the light emitted by the first communication device back to its light receiving element.
According to one additional development of the invention, the external interface element contains a connection or a cable for connection to a configuration/diagnostic device, e.g., a PC.
For certain operating modes, the external interface element contains a xe2x80x9clooped-throughxe2x80x9d optical waveguide that optically connects the light transmitting element and the light receiving element of the external interface element to one another. Consequently, this interface element may serve for xe2x80x9coptically short-circuitingxe2x80x9d the first communication device, i.e., the light transmitting element of the interface component can be optically connected to the light receiving element of the interface component via the external interface element.
The light transmitting element and the light receiving element, as well as the magnetically actuated switch, are arranged behind a transparent and magnetically permeable cover plate. The magnet is preferably so strong that the external interface element and, if applicable, the cable can be fixed on a vertically arranged cover plate of the light barrier arrangement solely by means of magnetic forces.
According to one additional development of the invention, the external interface element and the light barrier arrangement are designed such that the first and the second light transmitting and light receiving elements are aligned relative to one another solely by means of the magnetic forces when xe2x80x9cattachingxe2x80x9d the external interface element to the light barrier arrangement such that flawless data transmission is ensured. In other words, the switch is only actuated when the optical elements are correctly aligned relative to one another.
According to another additional development of the invention, the light transmitting element, the light receiving element and the magnetically actuated switch are connected to control electronics, wherein a separate controller may be respectively assigned to the light transmitting element and the light receiving element.
Consequently, the invention allows simple placement of the external interface element on the light barrier arrangement and reliable data exchange via an infrared connection. In this case, the magnet that is integrated into the external interface element automatically actuates the switch and thus activates the interface for a change-over into the configuration or diagnostic mode.
Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter.